Lewis store Eldorado park

Ok so here goes my gran bought a washing machine from the lewis store in Eldorado park and has been experiencing a lot of problems with it ever since the second month she had it. She cannot spin dry her washing because everytime she uses the spin dry part and washes washing at the same time the water drains into the dryer, she went to their store and complained about it and one of the employees told her it's cause she over loads the washing machine,they have came out to check but replaced a motor which wasn't even the problem. She has stopped paying her account as she feels she cannot pay for something she isn't using upto date no one came out to check this washing machine and it has never been fetched to get checked out can someone please advise what to do next